The invention relates to polymeric compositions that may be used in paint applications.
There has been recent activity surrounding the development of polymeric compositions that may be used, for example, in road- or pavement-marking applications. Due to the surface and ambient conditions under which the paint is subjected, it is desirable that the paint composition meet a number of requirements. These requirements include, for example, adhesion to road surfaces, resistance to chemical attack by water and/or salt, abrasion resistance, minimal hazard involving any processing solvents, ability to adhere to or hold or retain a glass bead filler or overcoating, long-term weather resistance, ability to be applied under a wide variety of ambient temperature and road surface conditions, flowability or sprayability, good wetting action with respect to roadway surfaces, and flexibility (i.e., the ability to move as road surfaces expand or contract).
A number of materials have been proposed for road surface paint compositions. For example, U.S. Pat. No. 4,185,132 to Gurney proposes the use of co-curative materials, namely a cycloaliphatic amine and an aliphatic amine, in combination with a liquid epoxide. The above mixture is applied to the paved surface, and the mixture cures in-situ. U.S. Pat. No. 4,105,808 to McKenzie proposes a paint composition for application at elevated temperatures on traffic roadways. The composition includes a paint vehicle having a nonvolatile organic film-forming binder and a volatile solvent in which the binder is dissolved. McKenzie alleges that the above mixture forms a non-tacky paint film when applied as a thin coating and exposed to ambient temperatures. U.S. Pat. 4,460,625 to Emmons et al. proposes coating and impregnating compositions for applications to concrete which include several monomers, a polyvalent metal salt or complex, and an organic peroxide. U.S. Pat. No. 4,051,195 to McWhorter proposes curable compostions formed from epoxide resin/polyacrylate ester or polymethacrylate ester compositions.
Notwithstanding the above developments, these compositions often cure in a relatively slow time period. As an example, the tack free time is typically more than 60 minutes during which time the road must be blocked to apply the paint. The lengthy delay is particularly troublesome in view of the increasing traffic volume in high growth regions. Moreover, the durability of this paint is believed to be limited. Thus, there is a need in the art for a paint compositions which are faster curing and exhibit greater durability.
The present invention addresses the shortcomings alluded to above, and provides a polymeric composition for use in traffic paint exhibiting a fast cure rate as defined in greater detail hereinbelow. The composition comprises a polyfunctional urethane acrylate component, an epoxy component, and a polyfunctional amine component. Advantageously, the polyfunctional urethane acrylate component reacts with the polyfunctional amine component to form a secondary amine component. The formation of the secondary amine proceeds relatively quickly. The secondary amine then reacts with the epoxy component such that a chemically crosslinked or thermoset polymeric material is formed. The composition exhibits improved properties over conventional compositions, particularly two component epoxy system, in that the composition of the invention displays improved cure speed and improved durability.
The polymeric composition may be employed in a traffic paint composition. The traffic paint composition comprises the polymeric composition and a pigment.